Daniel

I asked about the license because it seems to be a good policy to ask before helping, just to be sure whatever one contributes to will be open for others What you said goes for my stuff as well: help yourself, just keep it open.

a google search for "avr gcc stepper motor" found two good links about controlling a stepper motor on the cheap with an atmega on the first result page: http://www.vimms.org/dbfstepper/docu.html http://www.instructables.com/id/Drive-a-Stepper-Motor-with-an-AVR-Microprocessor/

still looking forward to the arduino shield design. Can the existing DC motor shield be used to drive two stepper motors?

a google search for "avr gcc stepper motor" found two good links about controlling a stepper motor on the cheap with an atmega on the first result page: http://www.vimms.org/dbfstepper/docu.html http://www.instructables.com/id/Drive-a-Stepper-Motor-with-an-AVR-Microprocessor/

still looking forward to the arduino shield design. Can the existing DC motor shield be used to drive two stepper motors?

peter

thanks for the link, but i dont think i'm going to use that. for two reasons:

1. i want to harness the sweet toolchain that arduino has developed. being able to plug the board into a computer and program it in one easy step is a HUGE deal. moving away from arduino to a custom design means i'd have to essentially re-invent that wheel. been there, done that. no thanks.

2. the circuit i am designing uses the L297/L298 combo which means it can handle stepper voltages from 12-36v, meaning you can drive your stepper motors at their optimum performance, as well as making the controls much easier: from the microcontroller you only need to send pulses when you want a step, and tell it which direction to step. so easy!

as for the DC motor shield, to the best of my knowledge it can only be used to drive DC motors. i dont know enough about it to tell you conclusively though.

Another price item you might want to check out are the Schottky diodes: you'll need 24 of them, and they are not cheap: count on 50 cents each in small quantities. You have to buy in quantity 500 or 100 to get a good price.

I don't know much about motor drivers, but I think the 293D already includes the diodes.

just wanted to ping the group and let you know that i finished the first-go of routing this board. 4.5" x 6", which isnt too bad for a big board like this. its in the subversion repository above, so please check it out and let me know what you think.

However, the diagram is for a "Two Phase Bipolar Stepper Motor Control Circuit." My question is, can I use this same circuit in a Four Phase Unipolar application? More specifically, are the motors connected to the L298N in the same configuration, allowing me to use the L6210 for the diode bridge?

If not, can someone please suggest a proper diode to be used in this application? I'm looking at this part;

Just in case you didn't already know, there's a kit available for a stepper/servo shield. If your interest is more in doing stuff with the steppers than learning how to design drivers, that will get you running faster.

I don't have a suggestion for the diode array, since I've always used the L293D (which has built-in diodes) for small motor driving. For loads like relays, I just grab whatever 1N4000-series diode is handy. Not as convenient when you need several, of course.

@Hoeken Hey, What is the status of this thing now? I know that you have got the MakerBot going, which looks great- Does it run off this, or did this get somewhat abandoned?

I was thinking about making an open source stepper driver, one that would have a bit better performance than the easydriver (also cheaper if possible). I was looking at allegro all in one chips, as opposed to the L297/L298 combo, but I was having a tough time picking between them.

That said, am I right in thinking that you opted for easydrivers in the end?

I've been doing so much stepper driver webbing today, that I've almost lost my mind! After re-browsing quite a bit, I realize that makerbot uses the reprap stepper drivers, presumably, the ones hoeken developed?